What Captain Lorca and co. find is a mirror universe ruled by Terrans — a monstrous empire, against whom the galaxy’s non-human races are allied. Where the USS Discovery is part of the United Federation of Planets, a diplomatic organization charged with deep space exploration and defense, its counterpart Terran ship — the ISS Discovery — is by definition a vessel carrying out the orders of the fascistic empire and quelling rebel uprisings.

As they start investigating their position, the USS crew hypothesize that they switched places with their ISS equivalent. They also recognize that alternate versions of themselves exist within this newly discovered dimension. But as they seek to impersonate their counterparts in order to get themselves out of hot water, could this be their undoing?

The Plan

The team must play the parts of Terrans and avoid discovery.

Lorca orders his crew to pay close attention to adopting the characteristics of the Terrans as they put their plan into action. Lorca and Burnham plot to track down info on another Starfleet ship – the USS Defiant – which rebel intelligence suggests also found its way to the alternate reality. With Stamets out of action and the spore drive unusable, they hope to find a way home by figuring out how the Defiant managed to make it over. To do that, they need to access the classified information the only way they can – by making use of high-level access on board a Terran ship.

This involves the team taking on the identities of their Terran alter egos.

So Who’s Who?

Burnham helps to transform Tilly.

Burnham discovers that in the alternate reality, Tilly is the captain of the Discovery.

Terran Captain Lorca, meanwhile, at one time in charge of the ISS Buran, is a “fugitive,” wanted for the murder of Michael Burnham. In the alternate universe, Burnham is captain of the ISS Shenzhou but presumed dead.

According to Burnham, Lorca “attempted a coup against the Emperor.” The unnamed emperor is the leader of the Terrans.

She says, “I was sent to stop you. In the process, my shuttle was destroyed by one of your followers and I was killed. The Emperor laid waste to your ship in retaliation. It’s believed you escaped.”

She also points out that her body was never found, which means the plan they concoct to board the Shenzhou as Captain Burnham with Lorca as her prisoner should stand up. At least that’s what they hope.

Why They Might Fail

Danby Connor is a former colleague of Burnham's on the Shenzhou, and captain of the ISS Shenzhou in the mirror universe -- now dead in both realities.

There are already foreboding signs that the plan will go awry. Firstly, Lorca’s simplistic summary of the scheme: “We beam over, Burnham gets the info on the Defiant, we beam back — simple” has already been upended. Upon boarding, Burnham kills the Shenzhou’s new captain and assumes command, and Lorca finds himself being tortured in an “Agonizer Booth.”

Lorca’s “famous last words:” “Our very survival relies on our ability to maintain this cover, no matter what” look set to trip him up. Combined with a prophetic plea to rethink the plan from Saru, there’s every possible hint that they’re about to run into their alternative selves.

“Boarding the ISS Shenzhou, posing as your Terran selves?” says Saru. “That plan is an invitation for calamity. Captain, I beg you to reconsider.”

What It Means For the Series

Tilly, Stamets and Culber.

Running into their Terran counterparts would inevitably result in the plan falling apart, and could feasibly strand them in the alternate reality for good, if not see them end up dead. Let’s face it, though, that’s highly improbable. And if they should die, it’s unlikely to mean forever. Death isn’t final; the show has already shown us that.

But it would mean conflict. Because of the disparity in political climates between universes, the alternative reality versions display vastly different traits to the characters we know.

As Tilly says of her other self: “She’s like a twisted version of everything I’ve aspired to be. I’m gonna have nightmares about myself.”

These are hostile people and presumably won’t hesitate to attack, even if they end up killing alternative versions of themselves. This isn’t an accepting, liberal culture; it’s a culture that breeds fear resulting in aggression. Burnham says, “Terran strength is born out of pure necessity. Because they live in constant fear. Always looking for the next knife aimed at their back.”

It could also mean that although we seemed to lose fan-favorite Culber in this episode at the hands of Ash Tyler, we could yet see him again in this alternate reality. However he might come back into play, it looks like it will happen — with Culber actor Wilson Cruz tweeting this:

As for Tyler, audiences learned that he is more than likely a Klingon sleeper agent. Since he has no human counterpart in the alternate universe, will the USS crew learn his identity?

And if the USS Discovery did switch places with the ISS Discovery, this could have serious repercussions for their own universe. Could the Terran ship also be instrumental in helping to save the USS crew when things go awry? Our Starfleet crew could equally find themselves teaming up with the Klingons against the common Terran foe. Finally, will we find that the enigmatic yet “savage” Emperor is someone we already know? That’s highly likely.